The long term objective of this project is to restore control of motor and sensory function in individuals with central nervous system paralysis through the use of neural prostheses employing electrical stimulation. Specifically, neural prosthetic systems for control of hand-arm function provide the individual paralyzed with high cervical level spinal cord injury with enhanced manipulation skills, thus improving his/her independence in daily activities. The specific aim of this project is to develop an integrated multichannel implantable system which, when introduced clinically, will provide the user with simplified use of the system and enhanced functional capabilities. This will be provided through the use of implanted sensors for control and feedback, telemetry to transmit these signals transcutaneously, and the capacity for activating more muscles. The focus of this project is on the development of the advanced implantable hardware system and its evaluation. The system to be developed will integrate a multichannel telemetry system and a multichannel stimulator with an implanted joint angle sensor. The single telemetry/stimulation device will be designed and fabricated using low power microelectronic circuitry for activation of up to 12 muscles and telemetry of up to three joint angle sensors and two myoelectric channels. A single radiofrequency signal will be used to power the system and transmit stimulus and control commands. The telemetry/stimulator device will be hermetically sealed in titanium and conformally coated with epoxy and elastomer which are suitable for chronic implantation. Joint angle transducers employing Hall effect sensors, recording and stimulation electrodes, and lead interconnections also will be fabricated. The system will be evaluated in in vitro and in vivo testing to insure proper operation over time. Accelerated bench tests will stress the electronics. In vitro tests will provide observable performance in a continuously monitored environment. In vivo testing in a dog model will demonstrate the long term stability of performance of the implanted system over time. At the completion of these studies, we expect to have developed and completed the evaluation of an advanced system for neural prosthetic applications which is suitable for human application.